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PORecursive QuickSort suffering a StackOverflowException
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  1. PORecursive QuickSort suffering a StackOverflowException
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    copied!<p>I am working on a Recursive QuickSort method implementation in a GenericList Class. I will have a second method that accepts a compareDelegate to compare different types, but for development purposes I'm sorting a GenericList&lt;<code>int</code>>.</p> <p>I am recieving stackoverflow areas in different places depending on the list size.</p> <p>I've been staring at and tracing through this code for hours and probably just need a fresh pair of (more experienced) eyes. I definitely want to learn why it is broken, not just how to fix it.</p> <pre><code>public void QuickSort() { int i, j, lowPos, highPos, pivot; GenericList&lt;T&gt; leftList = new GenericList&lt;T&gt;(); GenericList&lt;T&gt; rightList = new GenericList&lt;T&gt;(); GenericList&lt;T&gt; tempList = new GenericList&lt;T&gt;(); lowPos = 1; highPos = this.Count; if (lowPos &lt; highPos) { pivot = lowPos; for (i = 2; i &lt;= highPos; i++) { if (this[i].CompareTo(this[pivot]) &lt;= 0) leftList.Add(this[i]); else rightList.Add(this[i]); } leftList.Add(this[pivot]); leftList.QuickSort(); rightList.QuickSort(); for(i=1;i&lt;=leftList.Count;i++) tempList.Add(leftList[i]); for(i=1;i&lt;=rightList.Count;i++) tempList.Add(rightList[i]); this.items = tempList.items; this.count = tempList.count; } } </code></pre> <p>Finished Product:</p> <pre><code>public void QuickSort() { Random random = new Random(); int i, j, lowPos, highPos, pivot; GenericList&lt;T&gt; leftList = new GenericList&lt;T&gt;(); GenericList&lt;T&gt; rightList = new GenericList&lt;T&gt;(); GenericList&lt;T&gt; tempList = new GenericList&lt;T&gt;(); if (this.Count &gt; 1) { pivot = random.Next(1,this.Count); for (i = 1; i &lt;= this.Count; i++) { if (i == pivot) continue; if (this[i].CompareTo(this[pivot]) &lt; 0) leftList.Add(this[i]); else rightList.Add(this[i]); } leftList.QuickSort(); rightList.QuickSort(); for(i=1;i&lt;=leftList.Count;i++) tempList.Add(leftList[i]); tempList.Add(this[pivot]); for(i=1;i&lt;=rightList.Count;i++) tempList.Add(rightList[i]); this.items = tempList.items; this.count = tempList.count; } } </code></pre>
 

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